The present invention relates to novel parabanic acid derivatives and pharmaceutically acceptable salts thereof and pharmaceutical compositions containing them as an active ingredient.
Diabetic neuropathy, diabetic cataract and diabetic microangiopathy such as diabetic retinopathy, diabetic nephropathy or diabetic dermopathy are known as intractable chronic diseases accompanied with diabetes. One of the causes of these diabetic complications is the participation of polyol metabolism. Namely, under nonphysiological conditions of hyperglycemia in diabetes, the utilization of glucose through polyol pathway increases by several times as high as normal conditions, and so the production of sorbitol is elevated by aldose reductase. Consequently, excessive accumulation of intracellular sorbitol is occurred in tissues such as peripheral nerve, retina, kidney, lens and artery. Under these conditions, cellular edema and functional disorders may be caused by abnormal intracellular osmotic pressure.
As a result of investigations for inhibitors against aldose reductase participating the production of sorbitol to develop new drugs for treatment and prevention of the said diabetic complications, the inventors have found novel parabanic acid derivatives having an excellent aldose reductase inhibitory activity.
An object of the present invention is to provide novel parabanic acid derivatives and pharmaceutically acceptable salts thereof having an excellent aldose reductase inhibitory activity. Another object of the invention is to provide pharmaceutical compositions containing these parabanic acid derivatives or pharmaceutically acceptable salts thereof as an active ingredient to treat diabetic complications.